Summary:
The request from the FB YV3 team, they want to unify the UART channel number.
Thus, we align the debug card UART selection sequence with yv3.
E0 BMC
E1 HOST
E2 BIC
E3 Expander Smart
E4 Expander SDB
E5 IOC T5 Smart
E6 IOC T7 Smart

Pull Request resolved: https://github.com/facebookexternal/openbmc.wiwynn/pull/1793

Test Plan:
1. Built and test pass on Grand Canyon.

2. Check there are no unexpected error logs in BMC /var/log/messages and SELs.

3. Check debug card 7-segment LED can show correct channel number.

Reviewed By: benwei13

fbshipit-source-id: 66559ce8cf